The Left parties and eminent nuclear scientists, who expressed apprehensions over the Indo-US nuclear deal on Thursday welcomed Prime Minister Manmohan Singh's assurances in Rajya Sabha but the main opposition Bharatiya Janata Party said they did not fully address concerns over the deal's future.

The Left parties said the prime minister's assurances could be accepted as the 'sense of the House' on the issue. "Let us assume it as the sense of the House resolution," CPI-M leader Sitaram Yechury mooted after Singh completed his hour-long reply to the seven-hour debate on the nuclear deal.

Yechury said the prime minister has held out assurances on 'many of the issues raised and therefore his reply to the short duration discussion on the nuclear deal be accepted as the 'sense of the House', which the Left parties have been demanding.

"I would like to suggest that at present let us accept these assurances by the prime minister," Yechury said in Rajya Sabha after Dr Singh's reply.

CPI National Secretary D Raja said Dr Singh had tried to respond to all issues raised by the Left parties as well as by senior nuclear scientists.

"Since the prime minister has not differed on concerns expressed by us, his assurances to Rajya Sabha can be considered as the sense of the house," he said.

In contrast, BJP Parliamentary Party spokesman V K Malhotra expressed dissatisfaction with the prime minister's statement saying he should have instead allowed a 'sense of House' resolution on the pact.

"Singh's statement did not thoroughly address our interests regarding the future of our nuclear reactors and deterrent capabilities, once the deal is through," he said.

Malhotra, whose party and its allies had sought President A P J Abdul Kalam's intervention over their demands for the sense of Parliament resolution on the nuclear deal, insisted that such a move by the government could have lent more credibility.

Senior BJP leader Yashwant Sinha said the prime minister did not touch many of the issues raised by him such as US opposition to Russia supplying fuel to Tarapore nuclear reactor and fast breeder programme not coming under the safeguards agreement.

Dr M R Srinivasan, former Atomic Energy Commission chairman and current member of AEC, said unless India makes the US accept explicitly the position the prime minister adopted and unless the bilateral agreement clearly reflected in black and white all assurances given by him, there will be no guarantee that in future what is deemed non-binding on India in today's legislation will be converted to binding clauses by future administrations in US.

He hailed the prime minister's invitation to scientists for a meeting in Delhi on August 26.

On the perpetuity clause, he said, "We will be discussing with the prime minister in detail to make sure the R and D and fast breeder technologies are not placed under safeguards and also on future choice on voluntary safeguards."

Former AEC chairman Dr P K Iyengar said "The prime minister has made so many commitments to answer the scientists as well as the Opposition's concern and at the same time he has not left out his commitment related to American decision."

Iyengar said India has to wait and watch how the US Senate and Foreign Relations Committee take the sense of the House that was observed.

Placid Rodruigues, former Director of Indira Gandhi Centre for Atomic Research, said, "I welcome the prime minister's categorical statement and assurances but we have to seriously discuss the separation plans in detail again."

He, however, said the prime minister is yet to satisfy the House about how he would intend to convert the unsafeguarded experimental breeder programme to some form of safeguard to all commercialised fast breeder after 2014.

The scientists said the prime minister has assured that India will be treated as de facto nuclear weapon state and it would follow that the nature of the safeguard to be negotiated on the Indian reactor would be voluntary safeguard rather than any that may be applicable to a non-weapon nuclear country.

Based on today's assurances, the safeguards will not be applicable to a non-nuclear weapon country since safeguard attracts only on fuel, nuclear material and derivative and "imported reactors could be the only one subjected to perpetuity safeguards," they said.